Sudden cardiac arrest (SCA), which is also known as Sudden Cardiac Death (SCD), is a leading cause of death among adults over the age of 40 in the U.S., and throughout the world. In the U.S. alone, more than 300,000 men and women of all ages experience SCA annually. Tragically, nearly nine out of 10 victims die. In relation to other common lethal conditions, the number of people who die in the US each year from SCA is roughly equivalent to the number of people who die from Alzheimer's disease, assault with firearms, breast cancer, cervical cancer, colorectal cancer, diabetes, HIV, house fires, motor vehicle accidents, prostate cancer and suicides combined. Accordingly, it is evident that SCA is a costly and disruptive medical affliction on our society.
A paramount of medicine is the fact that the steady circulation of blood is crucial to the proper functioning of the human body. The circulation of blood is governed by the heart, whose expansion and contraction is in turn controlled by a regular pattern of electrical impulses. When this pattern of electrical impulses becomes chaotic or overly rapid, SCA may take place. Tragically, the victim typically collapses and dies unless he or she receives proper medical attention. The most successful therapy for sudden cardiac arrest is prompt and appropriate defibrillation. A defibrillator uses electrical shocks to restore the proper functioning of the heart. A crucial component of the success or failure of defibrillation, however, is time. Ideally, a victim should be defibrillated immediately upon suffering a sudden cardiac arrest, as the victim's chances of survival dwindle rapidly for every minute without treatment. In fact, research has determined that the full survival of an out-of-hospital cardiac death is 5-7%, where full survival is understood as normal brain and heart function, and this statistic has not changed significantly in the past 15 years.
While defibrillators are commonplace within medical facilities, automated external defibrillators (AEDs) are increasingly being installed in public places. AEDs are typically located in emergency response vehicles, medical facilities, and many public buildings. Efforts have been made to improve the availability of AEDs, so that they are more likely to be in the vicinity of sudden cardiac arrest victims. Also, advances in medical technology have reduced the cost and size of AEDs. Some modern AEDs approximate the size of a laptop computer or backpack. Even small devices may typically weigh 10 pounds or more. Accordingly, they are increasingly found in public facilities (e.g., airports, schools, gyms, etc.).
Currently available AEDs, while effective, are still less than ideal for most situations. For example, while AEDs are readily available in public settings and are not complicated to use, it has been found that untrained bystanders typically cannot, or will not, utilize devices even when they are easily accessible. Even when one does attempt to utilize an AED in a public setting, it can be a challenge to actually locate an AED. Specifically, when a person suffers from SCA in an airport or public building in which multiple AEDs have been distributed, the victim's companion or a stranger would have to locate and run towards the nearest AED, pull the device off the wall, and return to the collapsed victim to render assistance. During that time, precious minutes may have passed. According to some estimates, the chance of surviving a sudden cardiac arrest is 90% if the victim is defibrillated within one minute, but that chance declines by 10% for every minute thereafter. A defibrillator design that reduces the time to defibrillation by even two to three minutes will save more lives.
Despite the increasing presence of AEDs in public places, a central problem with combating SCA still remains: approximately 80% of sudden cardiac arrests occur at a private home or residence, not at a public building. Until AEDs are readily available for use in generally private places, such as homes and in cars, their effectiveness will remain significantly limited. More specifically, until AEDs are designed to be conveniently and regularly carried by non-professional rescuers, and are designed for quick, uncomplicated use, the effectiveness of AEDs may remain limited.
Thus, there exists a need to make AEDs accessible such that they can be widely used in home settings by untrained, first-time users.